#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,string> ii;

#define N 55
#define M 21
#define INF 10000007
#define PI acos(-1)
#define rep(i,a,b) for(int i = a; i < b; i++)
#define reps(i,a,b) for(int i = a; i >= b; i--)
#define sc scanf
#define pc printf
#define pb push_back
#define F first
#define S second

string fir,sec;
int a,b;
pair<int,string>dp[N][N][10];

//0 for '(' started
//1 for ')' ended
//2 for '{' started
//3 for '}' ended
//4 for '[' started
//5 for ']' ended
//6 for nothing has happened till now
pair<int,string>go(int p,int q,int is)
{
    if(p == a && q == b){
        if(is == 0) return ii(0,")");
        else if(is == 2) return ii(0,"}");
        else if(is == 4) return ii(0,"]");
        else if(is == 1 || is == 3 || is == 5 || is == 6) return ii(0,"");
    }
    if(p == a){
        string now = "";
        if(is == 0) now = ")[";
        else if(is == 2) now = "}[";
        else if(is == 6) now = "[";
        for(int j = q; j < b; j++){
            now += sec[j];
        }
        now += "]";
        return ii(b-q,now);
    }
    if(q == b){
        string now = "";
        if(is == 0) now = "){";
        else if(is == 4) now = "]{";
        else if(is == 6) now = "{";
        for(int j = p; j < a; j++){
            now += fir[j];
        }
        now += "}";
        return ii(a-p,now);
    }

    pair<int,string> &ret = dp[p][q][is];
    if(ret.F != -1) return ret;

    ret.F = INF;
    ret.S = "";

    pair<int,string>dup;
    string now;
    if(fir[p] == sec[q]){
        dup = go(p+1,q+1,0);
        if(dup.F + 1 < ret.F){
            ret.F = dup.F + 1;
            if(is == 0){
                now = "";now += fir[p];
                ret.S = now + dup.S;
            }
            else if(is == 1){
                now = "(";
                now += fir[p];
                ret.S = now + dup.S;
            }
            else if(is == 2){
                now = "}(";now += fir[p];
                ret.S = now + dup.S;
            }
            else if(is == 3){
                now = "(";now += fir[p];
                ret.S = now + dup.S;
            }
            else if(is == 4){
                now = "](";now += fir[p];
                ret.S = now + dup.S;
            }
            else if(is == 5){
                now = "(";now += fir[p];
                ret.S = now + dup.S;
            }
            else if(is == 6){
                now = "(";
                now += fir[p];
                ret.S = now + dup.S;
            }

        }
    }

    dup = go(p+1,q,2);
    if(dup.F + 1 < ret.F){
        ret.F = dup.F + 1;
        if(is == 0){
            now = "){";
            now += fir[p];
            ret.S = now + dup.S;
        }
        else if(is == 1){
            now = "{";
            now += fir[p];
            ret.S = now + dup.S;
        }
        else if(is == 2){
            now = "";
            now += fir[p];
            ret.S = now + dup.S;
        }
        else if(is == 3){
            now = "{";
            now += fir[p];
            ret.S = now + dup.S;
        }
        else if(is == 4){
            now = "]{";
            now += fir[p];
            ret.S = now + dup.S;
        }
        else if(is == 5){
            now = "{";
            now += fir[p];
            ret.S = now + dup.S;
        }
        else if(is == 6){
            now = "{";
            now += fir[p];
            ret.S = now + dup.S;
        }
    }
    dup = go(p,q+1,4);
    if(dup.F + 1 < ret.F){
        ret.F = dup.F + 1;
        if(is == 0){
            now = ")[";
            now += sec[q];
            ret.S = now + dup.S;
        }
        else if(is == 1){
            now = "[";
            now += sec[q];
            ret.S = now + dup.S;
        }
        else if(is == 2){
            now = "}[";
            now += sec[q];
            ret.S = now + dup.S;
        }
        else if(is == 3){
            now = "[";
            now += sec[q];
            ret.S = now + dup.S;
        }
        else if(is == 4){
            now = "";
            now += sec[q];
            ret.S = now + dup.S;
        }
        else if(is == 5){
            now = "[";
            now += sec[q];
            ret.S = now + dup.S;
        }
        else if(is == 6){
            now = "[";
            now += sec[q];
            ret.S = now + dup.S;
        }
    }

    return ret;

}

int main()
{
    int tt = 0;
    int T;
    sc("%d",T);
    while(++tt <= T){
        for(int i = 0; i < 55; i++){
            for(int j = 0; j < 55; j++){
                for(int k = 0;k < 10; k++){
                    dp[i][j][k].F = -1;
                    dp[i][j][k].S = "";
                }
            }
        }

        cin >> fir >> sec;

        a = fir.size();
        b = sec.size();

        pair<int,string>ans = go(0,0,6);
        pc("Case %d:\n",tt);
        cout << ans.F << "\n" << ans.S << endl;
    }




    return 0;
}